Samsung Galaxy S5 Problems

A

AC Question

I've had my galaxy for about a year now with no problems until about 2 months ago. I noticed that the battery life had become significantly shorter than it was when I first got the phone so I ordered a second battery. When I got the new battery I decided to use the old one as a spare, if my good battery died I could just pop in the old one for a few extra hours of life. A few weeks after I stated doing this the phone started having trouble turning on, the galaxy 25 logo would pop up on the screen as usual, but it would last a few seconds longer than normal and then the screen would go black ad the phone would buzz like it was turning off and then turn back on again and the same thing would happen. This would usually repeat anywhere from 2-10 times before the phone finally turned on, but just yesterday the phone didn't turn on at all, it kept doing this until the battery eventually died and it still won't turn on after being charged.

Is there any way I can fix this or do I have to just get a new phone? I would like to get it to turn on at least 1 more time so that I can back up everything thats on it.